As viruses, parasites, and other pathogens spread, humans and other animals tend to team up with immediate family and peers to avoid outsiders as much as possible.
But could these instincts, developed to protect us from disease, lead to avoiding healthy people who simply look, speak, or live differently?
Jessica Stephenson, an assistant professor in the Department of Biological Sciences at the Kenneth P. Dietrich School of Arts and Sciences, co-authored a paper exploring the answer that was recently published in the Royal Society of London Procedure, B. series.
An example cited in the study showed that black garden ants were exposed to a fungus that was grouped into groups much smaller than the researchers could randomly predict, which was effective in limiting the spread of disease. Similar behaviors in 19 non-human primate species have also been held responsible for reducing the direct spread of parasites.
People share the same biological impulses to separate into modular social groups. However, as pathogens spread, people also tend to adopt a range of behaviors that are “hypervigilant and particularly error-prone,” the researchers wrote.
Jessica Stephenson. Photo credit: University of Pittsburgh
“It’s interesting and really disappointing,” said Stephenson. And how COVID-19 continues its spread, humans are even more susceptible to the impulse.
“During epidemics, people tend to become over-sensitive, so any type of physical abnormality someone has suddenly becomes a potential indicator of infection. We become a lot bigoted, we pay much more attention to things that set people apart from what we perceive to be our own phenotype. People who look and sound different from us, which naturally leads to a lot more xenophobia, ”said Stephenson, who heads the Stephenson Lab for Disease Ecology and Evolutionary Parasitology at Pitt.
An earlier Stephenson study published in The Biology Letters of the Royal Society In November 2019, it was shown how individuals differ in their response to possible infections. In both humans and the guppies she studied, the most susceptible to the disease showed the strongest avoidance.
During this study, male guppies were placed in a large tank flanked by a smaller one that contained a group of three female guppies that were visibly infected with parasites. Many men preferred to spend time around the female guppies despite the risk of contagion. But some male guppies avoided the other fish severely. The socially distant male guppies were later shown to be very susceptible to worm infections.
Stephenson said humans in general are “normal social animals in many of our behavioral responses to infectious diseases”. However, if people prefer the social urge to infection control, efforts such as global disease surveillance and centralized public health responses could be wasted, she said.
“That the vast majority of our species have largely squandered the potential benefits of these benefits is again in line with other social animals: the cost of social distancing itself can outweigh the cost of contracting the disease,” said Stephenson.
But people have one leg up on fish: access to information and means of virtual communication. Stephenson’s 2020 study found that virtual or non-virtual synchronous communication can mitigate some of the effects of the restriction. Computerized discussions can also encourage equal participation by minority groups.
“For some, no amount of zoom and FaceTime can offset the lost benefits of social interactions. These frustrating, albeit natural, behavioral decisions will cause COVID-19 to persist until what is perhaps our greatest advantage over other species facing emerging infectious diseases emerges: vaccination. ”
“We shouldn’t discriminate against different groups in our social distancing or in our efforts to work together to fight the virus,” she added. “But I think our natural, evolving tendencies would be to only connect within our ingroups. We need to combat this natural aversion to people who are different from us and don’t switch off. ”
Reference:
“New Infectious Diseases and the Challenges of Social Distancing in Human and Nonhuman Animals,” by Andrea K. Townsend, Dana M. Hawley, Jessica F. Stephenson, and Keelah EG Williams, Aug 12, 2020, Royal Society procedure B..
DOI: 10.1098 / rspb.2020.1039
“Parasite-induced plasticity in host social behavior depends on gender and susceptibility” by Jessica F. Stephenson, 20th November 2019, Biology letters.
DOI: 10.1098 / rsbl.2019.0557
